When a disk in an aggregate fails, Data ONTAP automatically initiates a replacement process using an available spare disk. If no spare disk of the exact same size (36 GB) is available, ONTAP's policy is to select a compatible spare disk that is larger (72 GB). It then partitions the larger disk to create a logical slice that matches the size of the failed disk. This process is officially termed "right-sizing." The aggregate's RAID group geometry is maintained, and the remaining space on the 72 GB disk is left unused. This ensures the aggregate can be rebuilt and exit the degraded state without manual intervention.

A: Using the disk "as is" is incorrect. The replacement disk must logically match the size of the other disks in the RAID group to maintain its structure.

C: ONTAP does not halt. It continues operating in a degraded mode and automatically begins the rebuild process as soon as it selects a spare, without a 24-hour time limit.

D: ONTAP is designed for automation and flexibility. It will not simply wait if a larger, usable spare is available; it will proceed with the right-sizing process.

1. NetApp ONTAP 9 Documentation

Disk and Aggregate Management Guide: In the section "How a failed disk is replaced by a spare disk

" the documentation states

"If no spare disks of the same size are available

ONTAP selects a disk with a larger capacity and right-sizes it to the size needed by the aggregate. Right-sizing a disk creates a partition on the disk that is the same size as the failed disk."

2. NetApp ONTAP 9 Documentation

Disk and Aggregate Management Guide: The section "How ONTAP selects spare disks" further clarifies the selection criteria

prioritizing same-size

same-type disks but allowing for the selection and right-sizing of larger disks if an exact match is not found. This confirms that waiting (Option D) is not the default behavior.